Safety-tread unit



June 12, 1923.

G. N. JEPPSON SAFETY TREAD UNIT Filed Sept. 8 1921 INVENTOR N. Jeppson Patented June 12, 1923.

GEORGE N. JEPPSON, OFJWORGESTER, MASSACHUSETTS, ASSIGNOR TO NORTON COM- PANY, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

SAFETY-T Application filed September 8, 1921.

T all whom it may concern:

Be it known that I, GEORGE N. JEPPSON, a citizen of the United States of America, residing at Worcester, in the county of Worcester and State of Massachusetts, have invented certain new and useful Improvements in Safety-Tread Units, of which the following is a full, clear, and exact specification.

This invention relates to safety treads and more particularly to a tread unit adapted to be removably fastened on a flooring or stair.

Numerous methods and materials have been used in the construction of floors having as their general purpose the formation of a wear-resisting surface and more recently the specific purpose of making such surfaces non-slipping. A common type of safety tread which is especially suited for stairways is formed of a grooved or reticulated metal framework carrying strips of lead or cement loaded with abrasive. Such treads have involved a metal nose which is exposed to wear and in the course of time becomes slippery and dangerous to pedestrians. It has been proposed to replace such treads by tiles of ceramic bonded abrasive grains. such as those described in the patent to Dodge No. 1,377,960, dated May 10, 1921.

Anti-slipping tiles of this general character have been laid either by embedding in a layer of cement or by fastening them to a floor by means of screws. It 1s, however, undesirable to provide a cement foundation for the tiles in certain instances, as in replacing worn out treads of other types or afiixing a safety tile on a stair which has been built without such an anti-slipping device. Furthermore, when the tiles are fastened to a floor with screws and are subjected to the shocks and strains of traflic, the tiles may become cracked or otherwise in jured because of the unequal distribution of such strains.

It is accordingly an object of my invenfion to provide a safety tread unit of tiles of bonded abrasive grains, which will be wear-resisting and anti-slipping for a long .20 period of time and yet'is adapted to be uickly but removably fastened to a stair or other flooring and readily substituted for a worn out safety appliance without necessitating rebuilding the tread foundation.

READ UNIT.

Serial No. 499,278.

Further objects will be apparent in the following disclosure.

In the accompanying drawings I have illustrated an anti-slipping tread which embodies the principles of my invention.

Figure l is a perspective View of a portion of a stair carrying one of my tread units; and

Fig. 2 is a section, on the line i.-.2 of Fig. 1, of the tread unit alone,

In accordance with my invention I have provided a tread unit, particularly adapted for stairs, which comprises a supporting plate carrying a set of antislipping wearresisting tiles of abrasive grains bonded preferably with acera-mic matcrial'as described in said patent to Dodge. These tiles are so shaped and so spaced as to form substantially the whole tread surface of the unit. \Vhile various shapes may be employed they are preferably in the form of small tessera which have a common plane surface which is uniform throughout its area. The tiles are preferably held in place on the support by being embedded in a cementitious matrix which is preferably of such a nature that the shocks and strains on the individual tiles are absorbed locally without transmission over such an area as to crack or injure the tread unit.

As illustrated in the drawings, one embodlment of this invention comprises a tread unit in which the supporting member conslsts of a sheet iron plate 1 of substantially rectangular shape bent up at least on one SldB to form a front edge 2 to hold the tiles in position on the nose of the tread. As shown, this plate is preferably made in the form of a shallow an, having all four edges turned up. An a. hesive layer 3 of a suitable matrix, such as an asphalt of high softening temperature, is used, this layer being shallow but sufiicient in quantity to unite the tiles to the pan and. hold them in position. Embedded in this cement layer are the small tiles 4 arranged in a tessellated formation. Since a series of steps of such structure in which the tessera are of the same size and shape would not afford a conspicuous nosing, ll preferably form a nose of each step of dis tinctive tiles, which may be either colored differently from the remaining tiles 4 or made of a special size or shape. its illustrated, these tiles 5 are longer than those in the rearand present a band formation to indicate the nose 6 clearly. The cement between the tiles may also be colored and thus emphasize the difference in the shape or size of the nosing tiles.

Discs or plates 7 of suitable material are provided with countersunk perforations 8 and are so placed as to register with perfor ations 9 located in the bottom of the pan at suitable intervals. Screws 10 are inserted through these perforations in the discs and pan and thence into the stair floor 11 to hold the tread as a whole in position. The screw heads fit into the countersunk holes so that they do not form projecting obstructions on the tread surface.

The complete tread unit may obviously be altered in size and shape to fit the surface to be covered and the means employed for fastening may also be modified to correspond with the material of which the floor foundation is made. It, however, is desirable that the tiles form a plane tread surface which receives, all of the trafiic wear and that they extend above the front edge of the pan so as to provide an anti-slipping nosing, which is preferably rounded, as shown, and make the tread safe for pedestrians.

Numerous modifications in my invention will occur. to those skilled in the art of making floor surfaces, but such applications are to be considered as included in the above specification and in the following claims.

I claim:

1.,An anti-slipping stair tread unit comprising a metallic base having an upturned front edge, a cementitious matrix thereon, a set of bonded abrasive tiles embedded therein and arranged in the rear of and projecting above said edge to form a substantially plane top surface and the nosing of the tread, and means whereby the unit may be secured to a stair floor.

2. An anti-slipping tread unit comprising a pan shaped metallic plate, a cementing material contained therein and adhering thereto, and a plurality of bonded abrasive tiles embedded in said cementing material, the top sides of the tiles being flat and lying within the same plane surface and projecting above an edge of the pan to form a nosing of the tread.

3. n anti-slipping tread unit comprising a metallic plate having an upturned front edge and a plurality of perforations through its bottom portion, an adhesive matrix on said plate, a plurality of bonded abrasive tiles embedded in said matrix with their upper surfaces exposed and lying in the same plane above the front edge, and blocks provided with holes alignedwith said perforations for fastening the uniton a foundation, the tiles adjacent the front edge of the tread being distinctive from the remainder of the tiles and forming a conspicuous nosing.

4. n anti-slipping tread comprising a shallow pan, a cementitious matrix in said pan, a plurality of ceramic bonded abrasive tiles embedded in said matrix in a tessellated formation, a row of distinctive tiles forming the nosing of the tread, said tiles having their upper surfaces in the same plane and above the ed e of the pan, and means for fastening sai tread to the floor upon which it is laid.

Signed at Worcester, Massachusetts, this 7th day of Sept. 1921.

GEORGE N. J EPPSON. 

